import unittest
import user_code
import importlib
import io
from contextlib import redirect_stdout
import re

class TestTask(unittest.TestCase):
    def test_withdraw_nonlocal_usage(self):
        with open("user_code.py", "r") as f:
            code = f.read()
        _dynamic_test(
            self,
            "nonlocal" in code,
            "The inner function uses 'nonlocal' to modify the balance.",
            "The inner function does not use 'nonlocal' keyword to modify the balance.",
        )

    def test_withdrawal_sequence(self):
        import user_code
        importlib.reload(user_code)
        f = io.StringIO()
        with redirect_stdout(f):
            user_code.bank_account()
        output = f.getvalue().strip().splitlines()
        _dynamic_test(
            self,
            len(output) == 3,
            "Three results are printed for three withdrawals.",
            f"Expected 3 output lines, got {len(output)}: {output}",
        )
        try:
            first = int(output[0].strip())
        except Exception:
            _dynamic_test(
                self,
                False,
                "First withdrawal returns new balance as integer.",
                f"First output is not an integer: {output[0]}",
            )
            return
        _dynamic_test(
            self,
            first == 800,
            "Balance after withdrawing 200 is 800.",
            f"Expected 800 after withdrawing 200, got {first}",
        )
        _dynamic_test(
            self,
            output[1].strip().lower().startswith('insufficient'),
            "Second withdrawal shows 'Insufficient funds' message.",
            f"Expected 'Insufficient funds', got: {output[1]}",
        )
        try:
            third = int(output[2].strip())
        except Exception:
            _dynamic_test(
                self,
                False,
                "Third withdrawal returns new balance as integer.",
                f"Third output is not an integer: {output[2]}",
            )
            return
        _dynamic_test(
            self,
            third == 700,
            "Balance after withdrawing 100 is 700.",
            f"Expected 700 after withdrawing 100, got {third}",
        )

    def test_balance_hidden(self):
        # Check that 'balance' is not accessible at module level
        import user_code
        importlib.reload(user_code)
        has_balance = hasattr(user_code, 'balance')
        _dynamic_test(
            self,
            not has_balance,
            "The balance variable is not accessible outside the outer function.",
            "The balance variable should not be accessible outside the outer function.",
        )

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

def normalize_text(text):
    text = text.lower()
    text = re.sub(r"\\s{2,}", " ", text)
    text = re.sub(r"\\s*([,:?])\\s*", r"\\1 ", text)
    return text.strip()

def change_var(code: str, var_name: str, value: str) -> str:
    # Not used in this test
    return code


test_main.py

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リスト、タプル、辞書のパッキングおよびアンパッキングの技術を探求し、より表現力が高く効率的なPythonコードの記述を目指します。

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変数のスコープの謎を解き明かし、ネストされた関数とクロージャが強力なカプセル化をどのように実現するかを学びます。

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チャレンジ：外側スコープ変数の変更

解答